India, April 26 -- T he Chytrid fungus is so tiny, it can only be seen under a microscope. Yet it is deadly to amphibians such as frogs, toads and salamanders. It slides into their skin, blocks water, salt and air uptake, and causes lethargy, weight loss, ulcers and eventually death. (It then bursts out of the slain creature, and moves on to infest others.) Discovered in the late 1980s, the fungus is believed to have driven 90 amphibian species extinct over the past 40-odd years, and is at risk of wiping out others. Genetic strains have been traced to the Korean peninsula. In 2018, an international study published in the journal Science traced its global spread to the expansion of commercial trade in amphibians. Localised infections became ...